Changes in accommodation and ocular aberration with simultaneous vision multifocal contact lenses

Area of Science:

• Ophthalmology and Optometry
• Vision Science
• Optical Engineering

Background:

• Understanding ocular aberration changes is crucial for evaluating contact lens (CL) performance.
• Simultaneous vision multifocal CLs are designed to correct refractive errors while managing accommodation.
• Previous research has explored aberration profiles with various optical designs, but multifocal CL specific changes require further investigation.

Purpose of the Study:

• To evaluate changes in ocular aberrations induced by different simultaneous vision multifocal contact lenses (CLs).
• To compare the accommodative response and higher-order aberrations (HOAs) between single vision and multifocal CLs.
• To assess the impact of accommodative stimuli on spherical aberration, coma, and overall HOAs.

Main Methods:

• Eighteen young adults were fitted with a distance-single vision CL and two aspheric multifocal CLs (PureVision Low Add, PureVision High Add).
• Accommodative response, spherical aberration (C(4)(0)), coma (C(3)(1), C(3)(-1)), and root mean square (RMS) of HOAs were measured using a Hartmann-Shack aberrometer.
• Measurements were taken under monocular conditions for two accommodative stimuli (-2.50 D and -4.00 D).

Main Results:

• No statistically significant differences in accommodative response were observed between single vision and multifocal CLs for either stimulus.
• Spherical aberration (C(4)(0)) significantly decreased and became more negative with accommodation for all tested CLs.
• Horizontal coma decreased significantly with accommodation for the single vision CLs, while vertical coma showed no significant changes. The RMS of HOAs decreased only with single vision CLs.

Conclusions:

• The studied multifocal CLs did not induce substantial changes in accommodative response compared to single vision CLs in young subjects.
• A significant reduction in spherical aberration with accommodation was observed across all tested CL types.
• Multifocal CLs appear to maintain accommodative function similarly to single vision lenses, with spherical aberration being a key changing component.